Nexperia USA Inc. BZX79-C75,133

Overview

BZX79-C75,133 from Nexperia is a ±5% tolerance Zener voltage regulator diode with nominal 75 V breakdown voltage at 2 mA test current, 170 Ω typical differential resistance, and 95 mV/K temperature coefficient at I_Z = 2 mA. It operates within −65 °C to +200 °C junction temperature range and delivers stable reference voltage in low-power analog circuits such as sensor biasing and power supply feedback networks.

For engineers reviewing the BZX79-C75,133 datasheet, BZX79-C75,133 pinout, BZX79-C75,133 application, or BZX79-C75,133 equivalent, this device is selected for precision voltage clamping, low-current reference generation, and overvoltage protection where ±5% tolerance and DO-35 package compatibility are design requirements.

Technical Context

This Zener diode functions in reverse-biased avalanche mode, maintaining a stable 73.5–79.0 V working voltage across its terminals when reverse current is held between 0.5 mA and 2 mA. Its 170 Ω typical differential resistance ensures predictable voltage shift under load variation, while the +95 mV/K temperature coefficient indicates positive drift with rising junction temperature-critical for thermal compensation design.

The device is rated for 400 mW total power dissipation at T_amb = 50 °C (with PCB mount, no metallization pad), and supports non-repetitive peak reverse power dissipation up to 40 W for 100 μs pulses. Its 35 pF capacitance at 1 MHz and 0 V reverse bias makes it suitable for DC and low-frequency stabilization, not RF applications.

Key Specifications

Pinout & Package

Hermetically sealed glass SOD27 (DO-35) package with axial leads; cathode identified by a colored band on the glass body. Leads are tinned copper-clad steel, compatible with wave and reflow soldering per JEDEC J-STD-020.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener voltage regulation applications.

Compared with BZX79-C75,133, the 1N4744A serves entirely different voltage ranges and cannot replace it functionally, while the BZX85C75 offers identical regulation voltage but superior thermal performance and mechanical robustness at the cost of larger footprint and higher cost.

Availability

BZX79-C75,133 is available at Aetrix Electronics and suitable for industrial sensor conditioning, AC/DC adapter feedback protection, and PLC input surge suppression requiring stable component supply across multi-year production cycles.

Supply support for BZX79-C75,133 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Nexperia is a global leader in discrete, logic, and PowerMOS semiconductors, serving automotive, industrial, computing, and consumer markets with high-volume, high-reliability components.

The BZX79 series belongs to Nexperia's standard Zener diode portfolio, engineered for cost-sensitive, space-constrained applications requiring stable voltage references and transient protection in leaded through-hole packages.

FAQ

What is the maximum continuous reverse current this diode can handle at 75 V?

The BZX79-C75,133 is rated for 2 mA test current, but its absolute maximum continuous reverse current is limited by power dissipation: at 75 V, I_Zmax = 500 mW / 75 V ≈ 6.7 mA at T_amb = 50 °C. Derating applies above that ambient temperature per R_{th j-a} = 380 K/W.

Can this Zener be used in surface-mount designs?

No - the BZX79-C75,133 uses an axial-leaded SOD27 (DO-35) glass package designed exclusively for through-hole mounting. For SMT equivalents, consider Nexperia's BZX384-C75 (SOD-323) or PZM7.5NB (SOT-23), which differ in voltage tolerance, thermal resistance, and package dimensions.

How does the +95 mV/K temperature coefficient affect circuit accuracy?

A +95 mV/K coefficient means the Zener voltage increases ~7.1 V over a 75 K rise (e.g., from 25 °C to 100 °C junction). In precision references, this must be compensated via resistor networks or matched TC components; uncorrected, it introduces ~9.5% error across that range.

Is the cathode band polarity consistent across all BZX79-C variants?

Yes - all BZX79-C series diodes use identical SOD27 packaging with the cathode marked by a single color band on the glass body. The band always identifies the cathode terminal, regardless of nominal voltage or tolerance grade, ensuring consistent PCB layout and assembly orientation.